Contrlling atmosphere within reaction equipment



nJune 9, 1942.

J. R. BATES CONTROLLING ATMOSPHERE WITHIN REACTION EQUIPMENT Filed April 6, 1939 INVENTOR d n HN RBA-rcs ATTORNEY or converters.

Patented June 9, 14942 CONTROLIJNG ATMOSPHERE WITHIN REACTION EQUIPMENT John R. Bates, Swarthmore, Pa., assignor to Houdry Process Corporation, Wilmington, Del., a corporation ol' Delaware Application April 6, 1939, Serial No. 266,282

21 Claims.

The present invention relates to controlling the physical and/or chemical character of uid contained in reaction equipment by admission on tothe latter of fluid of a predetermined and controlled chemical nature. More particularly, it is concerned with processes and apparatus for diluting, displacing or otherwise regulating the nature of reaction iluid within converterscontaining contact masses which influence desired changesin reactants, such as hydrocarbons and their derivatives, and which, as a result, acquire burnable deposits, especially when the converters a practical arrangement of converters and otherl are engaged in cyclic operation involving onstream periods when burnable reactants are fed thereto alternating with regeneration periods when the burnable deposit is removed by controlled combustion. More specifically, it is directed to preparation of fluid useful with respect to both reaction fluid and the contact mass and to admission of controlled amounts of such fluid to the reaction zone at predetermined intervals.

It has become well known practice to utilize selected fluid in operating cycles of the above described type to condition or regulate the nature of the flui-d or atmosphere within the converter One such use is to provide inert or substantially inert atmosphere within reaction zones between on-stream and regeneration peri-- ods to prevent mixing of burnable reaction fluid such as reactants or reaction products with air or other free oxygen bearing regenerating medium and the resulting formation of combustible or explosive mixtures. Another use of inert or other suitable fluid isin dilution of vapor phase reactants, as for example, of hydrocarbons, to insure maintenance of desiredvapor phase conditions within the reaction zone. Steam, because it can be generated readily and at relatively low cost, has been the dilutingor conditioning iiuid mostr commonly employed. In a number of instances it has been found that steam has a deleterious effect upon the catalytic o'r other activity of certain contact masses with a tendency toward shortening the commercial life of such masses.

One object of the invention is to provide a `gaseous medium of controlled composition suitable for admission to. converters and other equipcontaining solid contact material. ject is to accomplish the above without interfering with normal operations involving chemical reactions. Other objects will be apparent from the detailed description which follows.

One concrete embodiment of the invention is disclosed in the accompanying drawing which is l a somewhat diagrammatic 'now chart illustrating equipment for operation of a plant engaged in the transformation or treatment of hydrocarbons. f

Referring to the drawing, a suitable number of converters such as l to 9 are arranged. in a battery to eiect continuous transformation of a stream. of hydrocarbon charging4 material, for example, of higher boiling hydrocarbons such as gas oils and crude oil distillation residues into lower boiling products of the gasoline type. Each of the converters contains a suitable contact mass M of silicious or other nature capable oi promoting or assisting the desired reaction, such for example, as an active or activated blend or compound of silica and alumina of natural or synthetic origin which is used for on`stream periods, when hydrocarbons are admitted thereto,

, alternating with regeneration periods when carment. Another object is to provide such a medibonaceous and other burnable deposits resulting from ori-stream reactions are removed therefrom by controlled combustion. During on-stream periods the selected hydrocarbon reactants are led by line I0 into heater II wherein they are vaporized with or without the aid 'of a. diluting or vaporizing fluid and heated to desired or c onversion temperature. The heated reactants are then con-ducted to the converter battery by line I2 and manifold I3 connected by valved branches to each of the converters I to 9 While reaction products are vented from the battery by similar valved branches into manifold I4 and conducted by the latter to suitable further-treatment, such as fractionation in fractionator or bubble tower I5. For the regenerating periods, a regenerating medium containing free oxygen, such as air for example, is conducted from manifold I6 through the proper valved branch orV branches into the desired one or. number of converters while regen.- eration fumes issuing from thel latter discharge into a suitable manifolding sy tem such as indicatedby manifoldsl I1, I1a an I1b. In order to maintain continuous ow to the converter battery of reactants for both on-stream and regenerating periods, similar operating periods in individual members of a battery are alternated or staggered so that at the end of an operating Another obf Operation of the converters also involves on'e` or more purging steps following on-.stream periods, regeneration periods, or both, and preceding admission to the converter of reactants for the succeeding portion of the cycle. Such purging may involve use of suitable, and especially inert, gaseous medium to serve as diluting or displacing agent, in which case a gas having selected properties maybe supplied to manifold 31 and from there be admitted in desired quantity and at proper intervals to each of the converters l to 9 through the valved branches shown-while spent purging medium admixed with purged iiuid discharges into manifold 38 from which, if desired, the mixture may be vented from the system, as from valved line 38.J The purging step or steps, however, are eiected to advantage at subatmospheric pressure in which case vacuum may be applied to the converters, for example, after the manner disclosed in U. S. Patent 2,095,- 265, issued October 12, 1937 to J. H. Pew or 2,095,264, issued on the same date to A. E. Pew, Jr. As indicated in the drawing, vacuum for such purging may be produced in any known or desired manne;` in evacuation zone 40, connected to manifold. 38 by valved line 4I. When vacuum is employed, use of valved line 39 is omitted. Following a vacuum purging step a suitable fluid is admitted to the reaction vessel to raise the pressure in the same toward the level desired for the next step in the operation. Such uid, which preferably is incapable of forming explosive or other highly reactive mixtures with. either theuid'remaining within and near the contact mass after the purging step or with the reactants for the next operating step, may be supplied from any suitable source to manifold 31.

It has now been discovered that a greatly improved purging is effected by admitting to the chamber to which vacuum' is being applied a suitable gaseous ejecting or displacing medium.

having predetermined and controlled characteristics suitable for admixture with the next fluid to be admitted to the contact mass. "I'hese results are obtained inexpensively and without -increase in the amount ofpower necessary to` evacuatethe chamber within a given time. Moreover, supplementary to the above advantages and contrary to expectation, steam, ad-

mitted as purging uid during. evacuation hasl little if any tendency to shorten the commercial life of contact masses ordinarily adversely affected by it.

In effecting this purging step. vacuum, produced in a vacuum jet, pump or other known or desired evacuating device, is applied to one or more points in the chamber and a predetermined quantity of a suitable purging gas is fed to the chamber at' one or more separate points. The selected gaseous medium may be admitted to the chamber and the mass at any time during drawing of the vacuum. Its action is more pronounced, however, and the purging more complete when it is sent into the chamber during at least the f latter portion of the' evacuation period. For

practical purposes in commercial scale operation, a continuous stream of the gas is usually fed for substantially this entire period.

The amount of. gaseous agent that need be used is small and is but a fraction of the amount necessary to effect, if used at normal pressure, a

reasonably good purging and is below amounts which aiect to substantial extent the temperature of the converter and its contents. The quantity fed and the rate of its admission to the chamber are preferably below the pulling capacity of the jet or the like so that substantial vacuum within the chamber is obtained and maintained. In fact, in many if not most instances, the most complete removal of reaction fluid from the contact mass and the chamber is realized when the ow of gas into the chamber is so limited as to have very little if any effect on the absolute pressure within the latter, as forv example, to restrict the pressure increase caused by such gas to less than 6 or 8 inches of mercury,

I and preferably to below 4 inches of mercury.

Any gas suitable for admission to the contact.

mass and for admixture with reactants and reaction products in contact therewith is suitable for this purpose. It supplements and accelerates the action of "the vacuum in removing reaction fluid from the chamber Whether that fluid be adsorbed and/or absorbed in the contact mass or merely in the free space ofthe chamber. By continuing vfeeding of this agent after the vacuum is shut off it serves the additional purpose of adjusting the pressure in the con-verter toward the level desired for the next operation.

Since the ejecting agent mingles with reactants and reaction products of vthe operation it is preferable that it be inert or substantially so with,

respect to such material, typicalinert uids being steam, nitrogen, carbon dioxide or any desired mixtures of two or more of these. Such admission of gas to the chamber during its evacuation, in addition to accelerating the purging process has other significant and important process advantages including: (1) more complete removal of reactantsand/or reaction products;

(2) positive displacement of even the rarified atmosphere of such material from both within and around the contact mass; and (3) Provision 'within the chamber of an atmosphere of 'fluid 75 Moreover, the effect of small and even practically negligible quantities of purging gas on the completeness of removal of reaction uid from the mass and its container becomes more pronounced with decreasing absolute pressures and especially at pressures below 15 inches of mercury. The effect on the absolute pressure'of the added gas may be reduced to substantial extent or even practically eliminated by use of a condensible purging gas such as steam, and condensation of that portion of it which is drawn from the vchamber' with the purged gases in a' barometric or other suitable condenser disposed between the evacuator and the container for the contact mass, for example, after the manner disclosed in the aforesaid Patent 2,095,265.

'Ihe startling and pronounced effect of adding only small quantities of selected purging gas to equivalent, in many cases, to less than the volume of reaction uid released as gas from the chamber during the entire purging step. In many instances, less than half or a third of this quantity of purging gas reduces the 'amount of residual reaction uid by as much as 95%. In removing some types of reaction fluid, for example, heavy and high boiling hydrocarbons from adsorptive materials, the combined use of vacuum and a purging gas often ejects from the mass strongly held deposits -which,. heretofore, could not be removed by a practical purging process. As a result of the quantity of deposit tobe removed by burning is reduced reflecting' in a tendency to shorten the burning or regeneration period itself.

In the interests of eecting eilicientv and complete purging in a minimum of time, the vacuum p is preferably applied simultaneously to a multiplicity of points within the contact mass as described in the aforesaid U. S. Patent 2,095,265, as for example, through use of a plurality of perforated conduits embedded in the mass, as indicated in converter l of the drawing. By preference, and to further accelerate the purging step, as also indicated in converter I, the gaseous purging medium is admitted to the mass at a separate multiplicity of points thereby at least 20%. The .condensate separated from the regeneration fumes amounted to somewhat `more than one gram per liter of contact mass was not necessary to utilize an inert repressuring medium tq raise the pressure within the converter toward the level desired for the next step in the process, regeneration. Air was safely used for this purpose without danger 'of uncontrolled burning or explosion. Likewise, following a sim ilarly conducted purging step after the regeneration period, highly flammable hydrocarbon gas or vapor, for example, vaporized fresh charge for the ori-stream period, or vapors or fixed gas resulting from this transforming operation were safely utilized for this purpose.

According to certain aspects of the invention,

regeneration fumes issuing from one or more converters in the battery are utilized as a supply or source of suitable, and especially inert, gas valuable for use as conditioning fluid to effect or' assist in purging and/or repressuring of converters, for addition to onstream reactants, and for other purposes where gaseous fluid having controlled composition and ,properties is necessary or desirable for plant operation. Regeneration fumes, however, are not constant in composition for the entire course of a regeneration period.

of tar which was practically incapable of vaporization, was fed in vapor phase, at a rate of about one volume of liquid charge per hour for each volume of contact mass to and through a highly adsorptive blend of silica and alumina maintained at about 850 F. for operating periods of about 10 minutes. These runs were made under conditions as nearly identical as could be obtained. After each run was terminated the contact mass was subjected to a three minute purging operation, that conducted after the rst run being admission of steam to the converter at a rate of about two volumes per minute (standard conditions) for each volume of mass. Following the second run vacuum was applied for three minutes, reducing the absolute pressure within In most instances, a substantial and often the major portion of those produced in a regeneration period contain such high concentrations of free oxygen that they are unt for admission into converters or other reaction equipment which contains or is about to contain burnable fluid. Consequently, they invention involves segregation from regeneration fumes of a quantity having controlled composition, preferably containing less than 6% by volume of free oxygen. In many, if not most, regeneration procedures, the fumes change progressively in nature during the course of a single regeneration period, from a fluid free or substantially so of oxygen but containing substantial quantities of burnable components, to a combustion supporting medium containing as the converter to about 3 inches of mercury. For i deposit following each of the purging operations,

and the remainder of the mass was subjected toY regeneration by controlled combustion. The regeneration fumes were cboled to, condense any oil vapor carried over with them and the resulting condensate separated from the nue gases and measured. The analyses of the contact mass showed coky deposits to the amount of about the order of 6 grams for each liter of mass following the steam purging and vacuum purging steps, respectively. The coky deposit remaining after the use of steam and vacuum simultaneously was,

however, about 4.8'grams per liter, areduction of high asr.,15% by volume of oxygen. In such instances, it is fumes formed early in the regeneration period'that are segregated from the balance and utilized as process fluid.

In some instances and for some purposes, as for example, when the conditioning fluid is to be added to burnable reactants which are within or are entering the reaction equipment the selected portion of the products of the regenerating reaction maybe conducted directly to the desired point or points of use as conditioning fluid. For example, in the specific embodiment ofthe inyention disclosed in the drawing, the desired quantity of oxygenv free fumes entering manifolds I1, Ila and Ilb may be conducted by lines I8, 18a and/or lsb by manifold 43 and by line 44 to feed line I0 for addition to fresh feed therein. Excess regeneration fumes including those containing undesirably high quantities of oxygen may, if desired, be vented from the system, as through valved lines 20. By preference, however, the quantity of fumes made early in the regenv eration and desired for ultimate use as conditionburnable components and/or free oxygen present in the. fumes to yield a uid consisting essentially of inert gases, for example,of carbon dioxide and nitrogen, as when air-is utilized as regenerating medium.

The controlled combustion is'effected to best advantage with the aid of a combustion promoter. To this end, the desired portion of regeneration fumes leaving the lbattery of converters may be conducted through a suitable manifolding and conduit system to a catalytic combustion-zone comprising one or any desired number of converters, asv for example and as indicated in the drawing, by 4manifolds I1, Ila and lib, lines I8, I8a and I8b to `converters i8, 19a and `l9b containing any known or desired` combustion .promoter. Suitable combustion Ipromoters include metals and metal oxides selected, for example, from the group copper, nickel, chromium, iron. The promoter may or may not be supported by active or inert material such as silica or alumina ornaturally occurring or artificially prepared blends or compoundsof .these materials. When this aspect of the invention is followed, excess t fumes may be vented from the system at any desired point before the combustion zone, as by .use of valved lines 20.' Then, any desired kquantity of the inert fluid discharged from any or all the converters I9, |9a and l9b into lines 2|, 2|a

and 2lb may be conducted through manifold 22,

U. S. Patent 2,167,655. In such a case, valved line 23 will be closed off and the fluid in manifold 22 conducted under pressure through valved line 25 to the desired energy recovery equipment,

for example, to operate turbine 26 driving blower or compressor 21 to force regenerating medium through line 28 and into manifold I6. Then, purified fumes in lines 2|, 2Ia, and 2lb desired for use to assist the cyclic operation will be admitted to manifold 29 and line 24. in response to change in the concentration `of free oxygen in' the fumes traversinglines 2|, 2|a. and 2lb and during periods Ywhen this concentration is below a predetermined amount, as for example not in excess of by volume.

As stated above one valuable use forinert fluid -V is conditioning interiors of converters in the battery especially to assist'process steps eiected between combustion or regeneration periods. To this end, desired amounts of the inert fluid entering line 24 under suitable pressure may be.

-conductedto line 36 to be admitted to reactants in line I0 and/or to manifold. 31, Vas desired or required in. the latter, for purging and/or repress'uring purposes. When the puried. inert fumes are drawn into line 24 under pressure suitable for the desired use and at rates and 4times correlated with the rates vand times at which such fluid is needed or desired in the-oper- Y V'.afesisnoi ation oi the converter battery, they may be conducted directly*` from line 24 tothe-.desired point of their admission into the conversion system as Y process fluid, as by use of valved conduits 30 and 3|.v When these rates and times do not coincide,

use may be made of a surge tank or storage vessel 28 may, if desired.

' lsulting from regeneration contain 6% or less of unused oxygen depend upon the nature and amount of the deposit on the contact mass andregeneration procedure removes that deposit. In commercially practicable reactivation processes following treatment or conversion of hydrocarbons, for example, the free oxygen content of the combustion products usually remains below 6% for from a third to a half of the regeneration period and, in most instances, remains below 5% and often below 2% or 3% for the entire or substantially the entire rst third of the reactivation. early portion of the regeneration step areoften sufiicient in quantity to supply all inert process fluid desired in conducting the cyclic operations. For effecting or assisting in purging steps, half commercial operations involving vacuum purging, below 10%, and even 5% or less, of this portion of the regeneration fumes are all vthat Y need to be purified and conducted to the battery of converters for admission thereto during and/or after application of vacuum for purging and repressuring purposes. When the oxygen free regeneration fumes, with or without being subjectedv to catalytic combustion, are to be added to on-stream reactants to assist` in vaporizing phase condition, as for example by addition to fresh feed in line I0, as indicated in the drawing or to the reactants during their passage dicated in the copending applications of Albert G. Peterkin, Serial No. 65,013, filed February 21, 1936 which issued July 18, 1939 as U, S. Patent 2,166,176, and Serial No. 65,955,- led February 27, 1936 'which issued July 18, 1939 a's'U. S. Patent 2,166,177, and in the copending application of Eugene yJ. Houdry, Serial No. 51,770, filed November 27, 1935 replaced by substitute application, Serial No. 287,972 filed August 2, 1939, which issued .September 9, 1941, as Patent No. 2,255,060, quite large proportions vas up to 75%' of the oxygen free or 25% of the totalquantity of re-l generation fumes may be necessary, depending upon'the volume, boiling' range characteristics, and other properties of the reactant material. When such large. quantities of the regeneration fumes are used as process iiuid in producing the preferred aspect of the invention, it is sometimes desirable to supplement the output of energy recovery equipment such as turbine 26 with power obtained from another suitable source. 'I'he actual control of the times and/or rates of admission of the desired conditioning fluid into Storage and/or compressingv means f 'The time intervals dun'ng which the fumes re to some extent upon the rate at which the selected The fumes resulting from. the

and often a quarter of the fumes made during this third are more than ample; in fact, in many the same or to insure their maintenance in vapor through heating and/or separating zones, as inmanifold 29 and/or into manifold 43 maybe effected in direct response to analysis for oxygen of a' continuous sample of the fumes passing throughlines 2l, 2Ia and 2Ib,' or, with a little experience in conductingthe regeneration, simply by manipulation of valves 42, 42av and 42h at predetermined times. Y

One of thespeciflc operations to which the invention finds valuable application is the use of an active' contact mass comprising, for. example, a selectively `a'dsorptive blend of silica and alumina containing these two components in the weight ratio of at least `31/211, such as described in the United States Patents 2,078,945 and 2,078,951, issued May 4, 1937, to Eugene J. Houdry, alternately on stream in the transformation of higher boiling hydrocarbons into high anti-knock motor fuel, effected for example, in the temperature-range of 750 to 1000 F. and in regeneration in situ by combustion effected under such controlled conditionsthat the temperature of the mass does not exceed a predetermined v maximum, say 1100" F. For such an operation, a suitable high boiling charge, for example, a long gas oil cut or viscosity broken bottoms from Mid-Continent crude may be vaporized with the aid of a small amount of vaporizing uid and fed to thecontact mass at a rate'of about 4 volumes of liquid charge per hour `to each 5 volumes of contact mass for an operating period while maintaining the mass at a temperature oi the order of 825 to 880 F. and the reaction zone at a pressure of the order of 15 pounds per square inch gauge. the succeeding regenerating periods a suitable oxygen bearing regenerating medium, for example air, may be passed through the contact mass under a pressure of 50 to 60 pounds per square inch gauge at a rate of about 680 volumes of air, measured at standard conditions, to each volume of contact mass per hour. The exothermic heat of the regeneration reactions mayI be removed at controlled rate in any known or idesired manner, as for example by heat` exchange members (not shown) embedded Iin the contact mass as indicated in United States Patents #2,078,947, issued May 4, 1937 to Eugene J. Houdry et al., #2,078,948, issued May 4, 1937 to Eugene J. Houdry and #2,078,949, issued the same date to Eugene J. Houdry and the copending application of Eugene J. Houdry and Thomas B. Prickett, Serial No. 261,728, led March -14, 1939, so as to maintain the temperature ofthe mass within a predetermined range, preferably below a maximum of 1050 or of 1000 F. This process may conveniently be eiected ina 45 minute cycle in a plant wherein the contact mass is disposed in nine converters as shown in the drawing. In this cycle, periods ofxabout 15 minutes each for feeding the hydrocarbon charge and regenerating medium, respectively, may be utilized. The remaining 15 minutes may then be divided into about 7 minute and 4 minute vacuum purging periods following on-stream and reactivation re- 1 minute each for effecting the necessary valve changes at the end o f each step in the'cycle.

One' methodof operating a plantis to start individual members f the battery of converters in the cycle successively-andat minute intervals,

thus to provide three converters on stream, three early in there-'generation conducted within one converter -do not mingle with fumes containing relatively high concentrations of oxygen and made during later portions of the regeneration l in another converter. This may be realized by providing three combustion converters, such as indicated at I9, I9'a and I9b, respectively, manifolded -to successive groups of three of the converters I to 9, as indicated, and starting converters I, l, 1,3, 5, 8, 3, 6 and 9 on streamvin the sequence named. Thus, each combustion zone will at all times be receiving-the fumes from only 'one converter in the battery. For example, following the regenerating period in converter I,

the stream of regenerating medium istrans7 ferred from it to converter 2 .to start regenerztion in the latter; then, at the end of regener tion in converter 2, the regenerating medium is and I9b each receive continuous flow of combustion gases coming successively from converters in the groups l, 5 `and 8, and 1, 8 and 9, respectively. When this preferred arrangement is employed,l the combustion step is advantageously one involving the use of a contact mass capable of supplying the oxygen necessary to burn the hydrocarbon fluid, for example, one

comprising u or containing copper oxide mainl tained at a temperature of 800 F. or higher, as

disclosed, for example, in the copending applica'- tion of .Eugene J. Houdry, Serial No. 78,542, led

-- May 8, 1936 and'replaced by substitute applicawhich have supplied oxygen to the combustion processes eected in converters I9, I9a and I9b.

Oxidation of' the combustion promoters takes place automatically when the regeneration fumes entering these converters contain excess or unused oxygen, as is usually the case during the latter portions of a regeneration period. At suitable intervals, usually infrequent, a reducing medium containing hydrogen, for example, may be admitted to the combustion catalyst ,to restore to active metallic or oxide form portions of it which have been converted into inactive sulphates by sulphurous componentsfof .the regeneration fumes.I f

The fumes made in veach converter for about -the first 5 minutesl of each regeneration therein, following catalytic combustion, are substantially free of oxygen, at no time containing more than 4%j by volume of this material, and are valuable for use as conditioning liiuid. Upon further actions, respectively, and four intervs'alsy of aboutanalysis of the above described specific operation, it is evident thatr since everl, minutes one of the converters inthe battery starts in regeneration, there is a continuous iiow from the battery of desired iiuid having a low oxygen content and under pressure suitable for use in desired portions of the operation cycle. Thus, this fluid may be conducted-directly and without intervening storage to the desired POint or points of its use as process uid in the conversion system.

In operating, for example, according to the prel ferred aspect of the invention wherein. burned r tion, Serial No. 266,010, filed April 14, 1939 which regeneration fumes issuing from catalytic combustlon zones I9, lSa and i9?) are continuously utilized to supply motive or other energy, as by running a turbine such as 25, the desired quanverter l, valve 42a open for the next 5 minutes during the early stages of regeneration in converter 4, etc. f In the particular and specific operation described 10% of the fluid leaving converters I9, 4

` I8a and lsb and so conducted to line 31 is .more than adequate for admission into converters during and following application of vacuum thereto to assist in the purging. operation and to raise the pressurain the reaction zones to substantially the desired operating level. For example, when utilizing a preferred type of converter, namely, one containing substantial quantities of so-called free space and having a plurality of conduits embedded in the contact mass for admission of yreactant fluid thereto at a multiplicity of points and simultaneous withdrawal of reaction products therefrom at a separate multiplicity oi points as in converters of the general type and design disclosed in United States Patent #2,042,468 issued June 2, 1936, to Eugene J. Houdry, the aforesaid Patent #2,078,947, and in lthe aforesaid copending application of Eugene J. Houdry yand 'I'homas B.'Prickett,` Serial No.

by fractionation. Regeneration fumesl obtained normally from cyclic operations provide a prolific source of process fluid having predetermined and desired properties suitable and valuable for use in effecting this novel and eicient purging step and for other uses as process fluid.

This fluid being free lor substantially f ree of oxygen is incapable of providing dangerous or explosive mixtures when admitted to converters or other portions of a plant containing organic reaction fluid. When the conditioning fluid results from controlled combustion it consists substantially of inert material su'ch as carbon dioxide and nitrogen and is particularly valuable for admission to any desired point in a conversion system for any desired portion of a cyclic process conducted therein. Whether or not this fluid has been subjected to controlled combustion to destroy its content of burnable components it chemically resembles regeneration fumes formed as an integral part of the operation cycle, and, for this reason, it cannot, through poisoning or other action, shorten the commercially useful life of the catalytic or other contact mass. Moreover, it is made available from vwhat is normally excess or waste material ina simple operation which is coordinated with the cyclic process and which in no way interferes with even very complicated cyclic operations.

Some typical cyclic operations, other than the transformation of fhigher boiling hydrocarbons 261,728, led March 14, 1939, about 7.5% of the quantity of regeneration fumes produced during the first 5 minutes of regeneration in converter I or about 2.5% of the total flow from the battery are usually suillcient to raise the pressure in converters 3 and 4 from 3 to 5 inches of mercury (absolute pressure) to their respective operating levels for on stream and regeneration steps in repressuring steps occurring in this 5 minute interval. A further quantity of fumes having the desired composition representing about 5% of the ow from the battery is suiilcient for admission to the converters during each evacuation to assist- `and accelerate the purging process. The remaining 92.5% of the total fumes produced in the battery contain sulcient energy recoverable in` a turbine such as 26 to compress substantially all the regenerating medium supplied to the converter battery. l

In the practice of its various aspects, the in- I vention ilnds application in many processes of incoverable product from contact masses utilized.

to remove, by selective adsorption, one or more components from gaseous mixtures containing the same. By selecting a purging medium having a boiling point different from the boiling point or range of the ejected adsorbed material any small quantity of purging gas that may be discharged from the chamber under evacuation may, if desirable or necessary, be separated from the desired material by simple condensation or into lower boiling motor fuel described above, to whichthe various aspects of the invention find application, are, refining of distillate and residual hydrocarbons within the boiling ranges of motor fuels and lubricating oils with the aid of adsorptive masses, catalytic dehydrogenation and/or aromatization of, saturated hydrocarbons, catalytic polymerization of unsaturated hydrocarbons to yield higher boiling products, catalytic hydrogenation of polymers or of other distillate or residual hydrocarbons, refining of gases involving use of contact masses capable of removing sulphurous or other undesirable components, contact viscosity breaking or vaporization of heavy bottoms'to yield marketable fuel oils or cracking stocks, and catalytic oxidations and condensations of hydrocarbons and their derivatives.

I claim as my invention:

l. In effecting chemical reactions involving the use of solid contact material disposed in a reaction zone alternately on stream to assist reactions which form contaminating deposits thereon and in regeneration to remove said deposits, the steps of segregating from the products of regeneration' after their withdrawal from said reaction zone a portion containing less than 6% free oxygen capable of use as inert process fluid with reactant charge and as purging medium before and after on stream periods of operation, and utilizing said segregated material for at least one of said purposes.

2. In effecting chemical reactions involving the contact mass to assistin controlling lthe physical and chemical properties of the fluid content of said zone, comprising the steps of purifying of active components regeneration products withdrawn from said reaction zone` during a portion of a regeneration period when the oxygen content of said products is low, and of said withdrawn products admitting to the mass only resulting puried product. l

3. In eiecting chemical reactions involving the use of solid contact mass alternately Von stream to assist reactions which form burnable deposits thereon and in regeneration by conposit, the process of removing fluid reactants and reaction products from the mass and the vessel containing the same in at least one interval between 'on stream and regeneration periods with the aid of vacuum applied to said vessel,

simultaneously and while maintaining absolute trolled combustion to remove such deposit, the

process comprising the steps of subjecting to catalytic combustion products of said regeneration containing burnable fluid and no more than 6% of free oxygen to yield a substantially inert.- v fluid, and admitting inert uid so produced and segregated from regeneration products of higher concentration of oxygen to a reaction zone containing said mass.

4. In controlling cylic operations wherein a contact mass is used alternately in the treatment of hydrocarbons which form contaminating deposit thereon and in regener tion in place to remove said deposit by contro ed combustion, the process steps comprising'purging said mass of reaction uid between on stream and regeneration steps, subjecting to controlledv combustion ue gases issuing from'said mass during a regeneration period and having lowcontent of Y components capable of entering into combustion combustion products of regeneration a quantity i -of uid produced early in a regeneration period containing less than 6% free oxygen, and admitting said fluid into contact with said mass while the latter is under vacuum.

6. In preparing for reuse a contact mass which has become contaminated with burnable deposit as a result of its use on stream in assisting chempressure in said vessel not inexcess of about inches of mercury admitting to the same a quantity of gaseous purging fluid substantially less than enough to' effect by itself eicient purging of said mass to cooperate with the vacuum 'and accelerate removal of said reaction fluid, and

subsequently admitting reactants for the next1 operating period into contact with said mass.

8. In controlling operations wherein a contact mass is used alternately on stream to assist reactions which form contaminating deposit thereon and in regeneration to remove saiddeposit, the process of purging reaction fluid from said mass comprisingV the steps of applying vacuum to a multiplicity of points within the vessel'containing said mass to remove vreactants and reaction' products therefrom during at least one interval between on stream and reaction periods, simultaneously with application of said vacuum admitting an amount of an inert gaseous purging agent insulcient in itself to eect said purging to at least one other point in said vessel to increase the rate and completeness of removal of said reactants and reaction products from the same, and restricting the rate of admission of said purging agent'to saidsvessel -to such a low value that subatmospheric pressure below 15 inches of mercury is obtained within said vessel during application of said vacuum.

9. In controlling operations wherein an adsorptive contact mass is used alternately on stream to assist reactions which `form burnable contaminating deposits thereon and in regeneration by 'combustion to remove said depositv and involving purging ofiiuid reactants and reaction products from said mass between on stream and regeneration periods, the process of effecting such purging comprising the steps of applying vacuum to at least one point in said mass during at least one interval between on stream and regeneration periods, simultaneously with application of vacuum admitting a gaseous purging medium to at least one other point in ical reactionsfthe process steps comprising ad-v mitting an oxygen bea-ring regenerating medium to said mass for a regenerating period while maintaining the temperature of the latter below a predetermined maximum to remove said deposit by controlled combustion, purging said mass of absorbed and adsorbed reaction fluid in an interval between on stream and regeneration periods with the aid `of substantial subatmos` pheric pressure applied to said mass, obtaining from combustion products formed during a regeneration period a segregated quantity of ue gases substantially free of components capable of reacting with the iluidbeing purged from said m/ass, and admitting a small quantity of flue gases so obtained to said mass while'simultaneously maintaining substantial sub-atmospheric pressure to cooperate with the low pressure in removing reaction fluid from the mass..

'LIn controlling operations wherein a con-V tact mass is used alternately on stream to assist reactions which .form contaminating deposit thereon and in regeneration to remove said desaid mass, and limiting the volume of gaseous fluid so admitted to no more than the volume of adsorbed fluid removed from the mass during the purging period. I

10. In purging an adsorptive contact mass of l reaction fluid adsorbed therein, the process of pulling substantial vacuum on the mass and simultaneously and while maintaining the mass at substantial sub-atmospheric pressure, owing a small amount of a purging fiuidthrough said mass' insufficient to affect substantially the temperature of the latter, thereby to accelerate removal of reaction fluid from the same and to increase completeness of said removal.

1l. In' purging an adsorptive contact mass of reactionfluid adsorbed therein, the process of pulling substantial vacuum on the mass through a multiplicity of points distributednwithin and throughout the same, and simultaneously admit ting to said mass at a multiplicity of points a quantity of purging gas restricted to less than 6v volumes of such gas for each volume of said mass,

thereby to provide substantially uniform .and

-positive flow of iiuid across and out of said mass.

l2. In'preparinga ycontact mass for further use in a cyclic process involving alternating op- Y gaseous medium to the purged mass to raise its pressure toward reaction level.

13. In controlling cyclic operations wherein a contact mass is used alternately on stream to assist reactions'which form burnable deposit thereon and in regeneration by burning to remove ksaid deposit, the process steps comprising subjecting'said mass to vacuum between on stream and regeneration periods to remove adherent reaction fluid therefrom, segregating from combustion products of regeneration a quantity of iiuid producedY early in a regeneration period and containing less than 6% free oxygen, ad-

mitting said iiuid into contact with said mass while maintaining the latter under substantial vacuum 'and later discontinuing evacuation to terminate the purging step,but continuing ow of said iiuidto raise the pressure of the mass toward the level of. the next period of the operating cycle.

14. In veiiecting chem-ical reactions involving the use of solid contact materially alternately on stream to assist reactions which form contaminating deposit thereon and in regeneration to remove s aid deposit by combustion, the process 'steps of purging -said contact material of reaction iiuid between alternating operations at reduced pressure, segregating from products of regeneration which have issued from contact material early in a regeneration period a portion of such products having controlled and low oxidizing potential and consisting essentially of inert components, and admitting products so segregated to the purged contact material to raise the pressure toward that of the next operating period. j

15. In the treatment of organic reaction uid with the aid of solid contact material which accumulates burnable deposit as a result of said treatment and is periodically regenerated by` combustion, the process comprising segregating from the combustion products formed early in a regeneration period a quantity'of flue gas containing not in excess of about 3% by volume of free oxygen, and feeding said segregated flue gas together with on stream reaction fluid to said contact material.

16. yIn the operation of a battery of converters vcontaining contact mass used alternately but at spaced intervals to assist vapor phase changes in organic uids which leave burnable contaminating deposit thereon and therein and in regeneration in place by controlled combustion of said deposit, members of said battery being successively in regeneration so that there is substantially continuous flow of regenerating medium to and regeneration fumes from the battery, the process comprising effecting catalytic combustion of regeneration fumes issuing from said battery to destroy burnable componentsand increase the energy content of said fumes, utiliz- 17. In the operation of a battery of converters containing contact mass used alternately on stream to assist hydrocarbon reactions and in regeneration in place by controlled combustion of deposit formed on or in said mass as a result of said reactions, regenerating medium being flowed through at least one converter in the battery for a regenerating period and at the end of that period being transferred to another converter for a successive regeneration period in the latter to provide continuous flow of regenerating medium through the battery, the process comprising sending a continuous stream of regeneration fumes issuing from the battery through a single combustion zone containing a combustion catalyst maintained at combustion conditions, segregating from the stream of` viding a reaction chamber for containing a contact mass, valved conduits connected to said converter for selectively admitting organic uid and regenerating medium thereto, valved outlet conduits for selectively receiving and conducting organic reaction products and regeneration fumes from said converter, means providing a catalytic combustion chamber'connected with the outlet conduit for regeneration fumes for burning burnable components of said fumes, and means including a valved conduit for conducting Icombustion products from said combustion chamber to said converter, for admission to the latter as desired or required therein.

19. In apparatus for treating hydrocarbons, in

combination, a converter providing a reaction chamber for containing a contact mass, said converter being arranged and adapted for use alternately in the treatment of hydrocarbons and in regeneration in place and being selectively connected to sources of hydrocarbon reactants and oxygen bearing regenerating medium, a valved conduit for conducting hydrocarbon reaction products from said converter, a second converter providing a reaction zone containing a contact mass capable of promoting combustion of burnable components in a stream of uid containing the same, a conduit interconnecting said converters for conducting regeneration fumes from the i'irst named to the second named converter, means adapted and arranged to utilize energy content of said fumes, a conduit interconnecting said last named converter and said means for conducting burned fumes from the former to the latter, and valved conduit means combination, a plurality of converters, each proing burned iume'sto supply industrial energy,-V

separating a` small portion of the burned fumes from the stream of the-same issuing from said battery, eiecting said separation in response to lconcentration of oxygen in said fumes and while the burned fumes contain less than 5% oxygen,

and admitting fumes so separated to a converter I as a process fluid for said operation cycle.

viding a reaction chamber for containing a conta'ct mass and arranged and adapted for use alternately on stream in the treatement of hydrocarbons and in regenerationof the mass in place, means for producing vacuum selectively -connected to each of said converters, a vessel providing inlet and outlet connections and enwclosing`a reaction chamber for containing a combustion catalyst, valved conduits selectively connecting said converters with said inlet connection for conducting regeneration fumes from the former to said vessel, and conduit means in- 4cluding a4 manifold and valved branches selectively connecting said outlet connection and each of said converters for periodically conducting regeneration fumes issuing from said vessel to each of said converters to serve as purging iluid there- 21. In apparatus 4for the treatment of hydrocarbons, in combination, a battery of converters, each providing a reaction chamber for containing a contact mass. and being arranged and adapted for use alternately on stream in the treatment of hydrocarbon charge and in regeneration of said mass in place, a reaction vessel providing a combustion zone, valved conduit means selectively connecting said converters with' said reaction vessel for conducting regeneration fumes to the latter, avcompressor selec- 

